A Display Port is a standard interface in digital audio and video signal transmission with high frequency transmission rate of 10.8 Gb/s. A computer connects to an LCD, plasma or CRT monitor or a projector through the Display Port to improves color saturation, resolution and refresh rate of a monitor. The transmission quality of the Display Port may be unstable at high frequency.
Recently, a Mini Display Port provides functions of a Display Port but is smaller replaces conventional Display Ports. With reference to FIG. 1, a conventional Mini Display Port (2) comprises at least one terminal (21), a first casing (22), a second casing (23) and a third casing (24). The first casing (22) has a ground element (221). The second casing (23) connects to the first casing (22) by welding. The third casing (24) electrically connects to the second casing (23) by a flexible unit or spot welds (231). The three casings (22, 23, 24) may not connect perfectly to each other or an external force may reduce the transmission efficiency at high frequency.